Field of the Invention
The invention relates to an optical device and an optical apparatus, and particularly relates to an optical diffusion plate and a light source module.
Description of Related Art
With the development of optical technology, light beam provided by a conventional backlight module can be used for lighting application or as the desired light source of the LCD display screen. In the conventional backlight module, a direct type backlight module can provide sufficient light beam to illuminate a large-sized display panel, and thus the large-sized display panel can display a good image.
In the current research and development objectives in the display technology, a thin display device having a high luminance has been one of the main issues currently. However, when the thickness of the display device is decreased, the distance between the light source in the direct type backlight module and the display panel may be decreased, so that the light beam emitted from the light source may not provide a uniform lighting effect. The conventional direct type backlight module may adjust the light beam by the optical lens, so that the light beam emitted from each light source can illuminate a larger region. However, when the thickness of the display device is further decreased, the distribution density of the light source and the optical lens is increased accordingly. Additionally, the light source and the optical lens in a high density not only decrease the manufacturing yield of the display device, but also increase the manufacturing cost of the display device at the same time.
The information disclosed in the “BACKGROUND OF THE INVENTION” section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Further, the information disclosed in the “BACKGROUND OF THE INVENTION” section does not mean that one or more problems to be resolved by one or more embodiments of the invention was acknowledged by a person of ordinary skill in the art.